feat(caddy): add tls internal vhosts for upstream mirror hosts

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

caddy/Caddyfile

@@ -1,5 +1,9 @@
+# auto_https off would disable TLS entirely, breaking `tls internal` for the
+# air-gap mirror vhosts. disable_redirects keeps the apex/auth/packwiz sites
+# plaintext on :80 (they use explicit http://) while still allowing internal
+# TLS on the mirror hosts below.
 {
-	auto_https off
+	auto_https disable_redirects
 }
 
 http://{$BASE_DOMAIN} {
@@ -15,3 +19,13 @@ http://packwiz.{$BASE_DOMAIN} {
 	root * /srv/pack
 	file_server browse
 }
+
+# Full client air-gap mirror (see plan/11-full-airgap-mirror.md): byte-exact
+# copies of the real upstream hosts served over HTTPS with Caddy's local CA.
+# dnsmasq spoofs these hostnames -> our host; the {host} placeholder roots each
+# hostname at its own mirror subtree. Guests import the Caddy root CA once.
+meta.prismlauncher.org, piston-meta.mojang.com, piston-data.mojang.com, libraries.minecraft.net, maven.neoforged.net, resources.download.minecraft.net {
+	tls internal
+	root * /srv/mirror/{host}
+	file_server
+}

docker-compose.yml

@@ -35,7 +35,7 @@ services:
     restart: unless-stopped
     ports:
       - "80:80"
-      # - "443:443"            # future TLS (step-ca), deferred
+      - "443:443"              # tls internal — air-gap mirror vhosts (see 11)
     environment:
       BASE_DOMAIN: ${BASE_DOMAIN}
     volumes:
@@ -43,11 +43,19 @@ services:
       - ./www:/srv/www:ro
       - ./pack:/srv/pack:ro
       - ./mirror/launcher:/srv/www/launcher:ro
+      - ./mirror/upstream:/srv/mirror:ro   # byte-exact upstream mirror (see 11)
     networks:
       mcnet:
         aliases:
           - "auth.${BASE_DOMAIN}"
           - "packwiz.${BASE_DOMAIN}"
+          # Air-gap spoof hosts -> Caddy, so internal containers resolve them too.
+          - "meta.prismlauncher.org"
+          - "piston-meta.mojang.com"
+          - "piston-data.mojang.com"
+          - "libraries.minecraft.net"
+          - "maven.neoforged.net"
+          - "resources.download.minecraft.net"
 
   drasl:
     image: unmojang/drasl:latest